PT  - JOURNAL ARTICLE
AU  - Tapan Kumar Mohanta
AU  - Abdullatif Khan
AU  - Abeer Hashem
AU  - Elsayed Fathi Abd_Allah
AU  - Ahmed Al-Harrasi
TI  - The Molecular Mass and Isoelectric Point of Plant Proteomes
AID  - 10.1101/546077
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 546077
4099  - http://biorxiv.org/content/early/2019/02/10/546077.short
4100  - http://biorxiv.org/content/early/2019/02/10/546077.full
AB  - A proteomic analysis of proteomes from 145 plant species revealed a pI range of 1.99 (epsin) to 13.96 (hypothetical protein). The molecular mass of the plant proteins ranged from 0.54 to 2236.8 kDa. A putative Type-I polyketide synthase (22244 amino acids) in Volvox carteri was found to be the largest protein in the plant kingdom and was not found in higher plant species. Titin (806.46 kDa) and misin/midasin (730.02 kDa) were the largest proteins identified in higher plant species. The pI and molecular weight of the plant proteome exhibited a trimodal distribution. An acidic pI (56.44% of proteins) was found to be predominant over a basic pI (43.34% of proteins) and the abundance of acidic pI proteins was higher in unicellular algae species relative to multicellular higher plants. In contrast, the seaweed, Porphyra umbilicalis, possesses a higher proportion of basic pI proteins (70.09%). Plant proteomes were also found to contain the amino acid, selenocysteine (Sec), which is the first report of the presence of this amino acid in plants. Additionally, plant proteomes also possess ambiguous amino acids Xaa (unknown), Asx (asparagine or aspartic acid), Glx (glutamine or glutamic acid), and Xle (leucine or isoleucine) as well.